Melt one tablespoon of the butter and let cool slightly.
Place the eggs, flour, milk, seltzer water, maple syrup, vanilla, and the melted butter, and salt in a blender and blend until smooth and bubbly.
Let the batter rest for 30 to 60 minutes at room temperature.
Once the batter has rested, melt an additional 2 tablespoons of butter to use for greasing the skillet.
Heat an 8 to 10-inch skillet over medium heat. Brush the skillet generously with melted butter. Pour about ¼ cup of the batter into the pan to thinly cover the pan. Very quickly swirl the pan around, so the batter covers the pan.
After the crepe is golden on one side, after about 60 to 90 seconds, carefully use a rubber spatula to flip the crepe over. Cook for an additional 30 to 60 seconds and remove the crepes to a plate.
Repeat the process until the batter is gone, being sure to brush the skillet with butter in between each time.
Flour: Be sure to use whole wheat pastry flour or cake flour instead of traditional whole wheat flour or all-purpose cake flour. The pastry flour has less density, making a lighter crepe.Seltzer Water: Club soda may be substituted for seltzer water. For storage: Stack cooled crepes between pieces of parchment or waxed paper. Place them in an airtight freezer bag or sealed container and store in the refrigerator for 3 days or in the freezer for up to 2 months. Reheat in a dry skillet.Cook's Note: If making savory crepes, you can omit the maple syrup from the batter.